Intelligence is one of the most important ways in which we judge one another and is a powerful and emotive issue for parents, teachers, employers and even politicians. However, it is still difficult to find a majority of experts anywhere who would agree on an acceptable definition of intelligence, as well as on its implications for human behaviour.

The nature-nurture debate is a long-standing argument over the relative contributions of experience (nurture, environment, learning) and inheritance (nature, heredity, genetic predisposition) to the make-up of an individual. But, clearly, both genetic and environmental factors influence IQ and therefore measured intelligence can be attributed to an interaction between both of these factors.

It is important, however, to understand that no matter how heritable intelligence is, some aspects of it are still malleable, that is, heritability of a trait is a separate issue from its malleability. Consequently, there is little doubt that a programme of training can increase some aspects of a person's intelligence, however, no training programme, and no environmental condition of any sort, can make a genius out of a person who is not particularly bright in the first place.

Real intelligence is about understanding, and being aware of what is important, and reacting appropriately in the circumstances being experienced.